ETZ 251 gearbox blow up

[thomaskwscott]

Hi Guys,

I've just had to have my etz 251 recovered for the first time ever. The bike was running fine all morning, then I stopped and when I came to start it again there was nothing at the other end of the kick start! Thinking this was annoying but not disastrous we decided to give it a bump only to find that no matter what gear we put it in there was no connection between engine and back wheel. In fact, walking the bike around in gear resulted in a faint crunching noise that went away after the first few metres.

With the bike back home now I'm looking around for ideas of what could have gone wrong. So far I'm hoping that one of the oil side drive sprockets has come off its taper and its nothing more than that. This would explain the lack of connection between crank and gearbox but feels a little hopeful on my part. Any other things to check?

[DAVID THOMPSON]

my Father always said if the in and the out are no longer connected
something in the middle is slipping or "GONE missing"

dave

[Blurredman]

I hope for your sake that the clutch basket didn't come off. Although, it doesn't sound like it did.


What happens when you push it around in gear with and without the clutch disengaged?

[arry_b]

The only thing on the gearbox side on a tape is the clutch basket. Unlike Blurredman, I reckon that's what's happened.

Take the clutch adjuster cover plate off (three screws) and see if the nut holding the clutch basket onto the crank taper is loose.

[Blurredman]

The only thing on the gearbox side on a tape is the clutch basket. Unlike Blurredman, I reckon that's what's happened.

Take the clutch adjuster cover plate off (three screws) and see if the nut holding the clutch basket onto the crank taper is loose.

I just find it odd that it has broken when not in use. Although I wonder if the temperature cool down has popped the clutch off while it was resting? If that is the case, at least the crank taper and clutch inner tape would be intact.

[thomaskwscott]

The wierdthing is the clutch still seems to be operating fine (well apart from the fact that it doesn't do anything). There is plenty of resistance at the lever and if I pull it in it springs back right away. One of the other posts asked me to see what happens if I walk the bike around with clutch in and out and it makes no difference at all I've made a quick list of the symptoms below and they all point to the clutch basket unfortunately:

In gear and kicking kick starter - back wheel turns but engine doesn't
Neutral and kicking kick starter - no resistance on kick start at all
Walking round in gear clutch out - engine does not turn but bike moves freely
Walking round in gear clutch in - no difference to above

I'll take that clutch cover off asap and have a look.

[thomaskwscott]

I finally got the time to take the cover off and have a look at the clutch retension nut. Unfortunately the problem. The nut was tight and couldn't find any slack in the clutch assembly. On a side note there's now a loud grinding noise coming from the engine every time i spin the back wheel in gear. Looks like i'm going to have to strip it fully after all.